C2X adds a %b printf format to print integers in binary (analogous to %x, including %#b printing a leading 0b on nonzero integers), with recommended practice for a corresponding %B (where %#B uses 0B instead of 0b) where that doesn't conflict with existing implementation extensions. See N2630 for details (accepted for C2X, not yet in the latest working draft). There is also a scanf %b format.
Add corresponding format checking support (%b accepted by -std=c2x -Wformat -pedantic, %B considered an extension to be diagnosed with -Wformat -pedantic). glibc support for the printf formats has been proposed at <https://sourceware.org/pipermail/libc-alpha/2021-October/131764.html> (scanf support to be done in a separate patch). Note that this does not add any support for these formats to the code for bounding the amount of output produces by a printf function, although that would also be useful. Bootstrapped with no regressions for x86_64-pc-linux-gnu. Applied to mainline. gcc/c-family/ * c-format.c (print_char_table): Add %b and %B formats. (scan_char_table): Add %b format. * c-format.h (T2X_UI, T2X_UL, T2X_ULL, T2X_US, T2X_UC, T2X_ST) (T2X_UPD, T2X_UIM): New macros. gcc/testsuite/ * gcc.dg/format/c11-printf-1.c, gcc.dg/format/c11-scanf-1.c, gcc.dg/format/c2x-printf-1.c, gcc.dg/format/c2x-scanf-1.c, gcc.dg/format/ext-9.c, gcc.dg/format/ext-10.c: New tests. diff --git a/gcc/c-family/c-format.c b/gcc/c-family/c-format.c index ca66c81f716..c27faf71676 100644 --- a/gcc/c-family/c-format.c +++ b/gcc/c-family/c-format.c @@ -712,11 +712,14 @@ static const format_char_info print_char_table[] = /* C99 conversion specifiers. */ { "F", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN, TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#'I", "", NULL }, { "aA", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN, TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#", "", NULL }, + /* C2X conversion specifiers. */ + { "b", 0, STD_C2X, { T2X_UI, T2X_UC, T2X_US, T2X_UL, T2X_ULL, TEX_ULL, T2X_ST, T2X_UPD, T2X_UIM, BADLEN, BADLEN, BADLEN }, "-wp0#", "i", NULL }, /* X/Open conversion specifiers. */ { "C", 0, STD_EXT, { TEX_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL }, { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "R", NULL }, /* GNU conversion specifiers. */ { "m", 0, STD_EXT, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "", NULL }, + { "B", 0, STD_EXT, { T2X_UI, T2X_UC, T2X_US, T2X_UL, T2X_ULL, TEX_ULL, T2X_ST, T2X_UPD, T2X_UIM, BADLEN, BADLEN, BADLEN }, "-wp0#", "i", NULL }, { NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL } }; @@ -876,6 +879,8 @@ static const format_char_info scan_char_table[] = /* C99 conversion specifiers. */ { "F", 1, STD_C99, { T99_F, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN, TEX_D32, TEX_D64, TEX_D128 }, "*w'", "W", NULL }, { "aA", 1, STD_C99, { T99_F, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN, TEX_D32, TEX_D64, TEX_D128 }, "*w'", "W", NULL }, + /* C2X conversion specifiers. */ + { "b", 1, STD_C2X, { T2X_UI, T2X_UC, T2X_US, T2X_UL, T2X_ULL, TEX_ULL, T2X_ST, T2X_UPD, T2X_UIM, BADLEN, BADLEN, BADLEN }, "*w", "W", NULL }, /* X/Open conversion specifiers. */ { "C", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*mw", "W", NULL }, { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*amw", "W", NULL }, diff --git a/gcc/c-family/c-format.h b/gcc/c-family/c-format.h index 2f926f4c8c1..2b5012ee3a9 100644 --- a/gcc/c-family/c-format.h +++ b/gcc/c-family/c-format.h @@ -278,13 +278,17 @@ struct format_kind_info #define T89_S { STD_C89, NULL, T_S } #define T_UI &unsigned_type_node #define T89_UI { STD_C89, NULL, T_UI } +#define T2X_UI { STD_C2X, NULL, T_UI } #define T_UL &long_unsigned_type_node #define T89_UL { STD_C89, NULL, T_UL } +#define T2X_UL { STD_C2X, NULL, T_UL } #define T_ULL &long_long_unsigned_type_node #define T9L_ULL { STD_C9L, NULL, T_ULL } +#define T2X_ULL { STD_C2X, NULL, T_ULL } #define TEX_ULL { STD_EXT, NULL, T_ULL } #define T_US &short_unsigned_type_node #define T89_US { STD_C89, NULL, T_US } +#define T2X_US { STD_C2X, NULL, T_US } #define T_F &float_type_node #define T89_F { STD_C89, NULL, T_F } #define T99_F { STD_C99, NULL, T_F } @@ -300,6 +304,7 @@ struct format_kind_info #define T99_SC { STD_C99, NULL, T_SC } #define T_UC &unsigned_char_type_node #define T99_UC { STD_C99, NULL, T_UC } +#define T2X_UC { STD_C2X, NULL, T_UC } #define T_V &void_type_node #define T89_G { STD_C89, NULL, &local_gimple_ptr_node } #define T_CGRAPH_NODE { STD_C89, NULL, &local_cgraph_node_ptr_node } @@ -314,16 +319,19 @@ struct format_kind_info #define TEX_WI { STD_EXT, "wint_t", T_WI } #define T_ST &size_type_node #define T99_ST { STD_C99, "size_t", T_ST } +#define T2X_ST { STD_C2X, "size_t", T_ST } #define T_SST &signed_size_type_node #define T99_SST { STD_C99, "signed size_t", T_SST } #define T_PD &ptrdiff_type_node #define T99_PD { STD_C99, "ptrdiff_t", T_PD } #define T_UPD &unsigned_ptrdiff_type_node #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD } +#define T2X_UPD { STD_C2X, "unsigned ptrdiff_t", T_UPD } #define T_IM &intmax_type_node #define T99_IM { STD_C99, "intmax_t", T_IM } #define T_UIM &uintmax_type_node #define T99_UIM { STD_C99, "uintmax_t", T_UIM } +#define T2X_UIM { STD_C2X, "uintmax_t", T_UIM } #define T_D32 &dfloat32_type_node #define TEX_D32 { STD_EXT, "_Decimal32", T_D32 } #define T_D64 &dfloat64_type_node diff --git a/gcc/testsuite/gcc.dg/format/c11-printf-1.c b/gcc/testsuite/gcc.dg/format/c11-printf-1.c new file mode 100644 index 00000000000..7b8a9928098 --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/c11-printf-1.c @@ -0,0 +1,13 @@ +/* Test for printf formats: rejection of C2X (and C2X-recommended) formats in + pedantic mode. */ +/* { dg-do compile } */ +/* { dg-options "-std=c11 -pedantic -Wformat" } */ + +#include "format.h" + +void +foo (int i) +{ + printf ("%b", i); /* { dg-warning "C" } */ + printf ("%B", i); /* { dg-warning "C" } */ +} diff --git a/gcc/testsuite/gcc.dg/format/c11-scanf-1.c b/gcc/testsuite/gcc.dg/format/c11-scanf-1.c new file mode 100644 index 00000000000..d2b9bfb23b5 --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/c11-scanf-1.c @@ -0,0 +1,11 @@ +/* Test for printf formats: rejection of C2X formats in pedantic mode. */ +/* { dg-do compile } */ +/* { dg-options "-std=c11 -pedantic -Wformat" } */ + +#include "format.h" + +void +foo (unsigned int *uip) +{ + scanf ("%b", uip); /* { dg-warning "C" } */ +} diff --git a/gcc/testsuite/gcc.dg/format/c2x-printf-1.c b/gcc/testsuite/gcc.dg/format/c2x-printf-1.c new file mode 100644 index 00000000000..3ae7713ff05 --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/c2x-printf-1.c @@ -0,0 +1,26 @@ +/* Test for printf formats. Formats using C2X features. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic -Wformat" } */ + +#include "format.h" + +void +foo (unsigned int u, unsigned short us, unsigned char uc, unsigned long ul, + unsigned long long ull, uintmax_t uj, size_t z, unsigned_ptrdiff_t ut) +{ + /* Use of %b with each length modifier and other valid features. */ + printf ("%b %hb %hhb %lb %llb %jb %zb %tb\n", u, us, uc, ul, ull, uj, z, ut); + printf ("%*.*llb\n", 1, 2, ull); + printf ("%-b\n", u); + printf ("%#b\n", u); + printf ("%08b\n", u); + /* Flags valid on signed conversions only. */ + printf ("%+b\n", u); /* { dg-warning "flag" } */ + printf ("% b\n", u); /* { dg-warning "flag" } */ + /* Flags ignored in certain combinations. */ + printf ("%-08b\n", u); /* { dg-warning "ignored" } */ + printf ("%08.5b\n", u); /* { dg-warning "ignored" } */ + /* Use of 'L' and 'q' for long long is an extension. */ + printf ("%Lb", ull); /* { dg-warning "does not support" } */ + printf ("%qb", ull); /* { dg-warning "does not support" } */ +} diff --git a/gcc/testsuite/gcc.dg/format/c2x-scanf-1.c b/gcc/testsuite/gcc.dg/format/c2x-scanf-1.c new file mode 100644 index 00000000000..f46a7152769 --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/c2x-scanf-1.c @@ -0,0 +1,17 @@ +/* Test for scanf formats. Formats using C2X features. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic -Wformat" } */ + +#include "format.h" + +void +foo (unsigned int *uip, unsigned short int *uhp, unsigned char *uhhp, + unsigned long int *ulp, unsigned long long *ullp, uintmax_t *ujp, + size_t *zp, unsigned_ptrdiff_t *utp) +{ + scanf ("%*b"); + scanf ("%2b", uip); + scanf ("%hb%hhb%lb%llb%jb%zb%tb", uhp, uhhp, ulp, ullp, ujp, zp, utp); + scanf ("%Lb", ullp); /* { dg-warning "does not support" } */ + scanf ("%qb", ullp); /* { dg-warning "does not support" } */ +} diff --git a/gcc/testsuite/gcc.dg/format/ext-10.c b/gcc/testsuite/gcc.dg/format/ext-10.c new file mode 100644 index 00000000000..370ea86b42e --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/ext-10.c @@ -0,0 +1,13 @@ +/* Test for scanf format extensions using formats from C2X. */ +/* { dg-do compile } */ +/* { dg-options "-std=gnu2x -Wformat" } */ + +#include "format.h" + +void +foo (u_quad_t *uqp, unsigned long long int *ullp) +{ + /* Deprecated length modifiers with %b. */ + scanf ("%qb", uqp); + scanf ("%Lb", ullp); +} diff --git a/gcc/testsuite/gcc.dg/format/ext-9.c b/gcc/testsuite/gcc.dg/format/ext-9.c new file mode 100644 index 00000000000..15f59e21dbe --- /dev/null +++ b/gcc/testsuite/gcc.dg/format/ext-9.c @@ -0,0 +1,29 @@ +/* Test for printf format extensions using formats from or recommended by + C2X. */ +/* { dg-do compile } */ +/* { dg-options "-std=gnu2x -Wformat" } */ + +#include "format.h" + +void +foo (u_quad_t uq, unsigned int u, unsigned short us, unsigned char uc, + unsigned long ul, unsigned long long ull, uintmax_t uj, size_t z, + unsigned_ptrdiff_t ut) +{ + /* Deprecated length modifiers with %b and %B. */ + printf ("%qb%qB", uq, uq); + printf ("%Lb%LB", ull, ull); + printf ("%Zb%ZB", z, z); + /* Use of %B in cases valid for %b. */ + printf ("%B %hB %hhB %lB %llB %jB %zB %tB\n", u, us, uc, ul, ull, uj, z, ut); + printf ("%*.*llB\n", 1, 2, ull); + printf ("%-B\n", u); + printf ("%#B\n", u); + printf ("%08B\n", u); + /* Flags valid on signed conversions only. */ + printf ("%+B\n", u); /* { dg-warning "flag" } */ + printf ("% B\n", u); /* { dg-warning "flag" } */ + /* Flags ignored in certain combinations. */ + printf ("%-08B\n", u); /* { dg-warning "ignored" } */ + printf ("%08.5B\n", u); /* { dg-warning "ignored" } */ +} -- Joseph S. Myers jos...@codesourcery.com
